The process of respiration is:

When a person breathes in air, the air enters into his body through an organ $A$ having two holes $B$ in it. The air then passes through pharynx and larynx and enters into a tube $C$. The tube $C$ divides into two smaller tubes $D$ at its lower end. The two smaller tubes are attached to two respiratory organs $E$. Each smaller tube divides inside the organs $E$ to form a large number of still smaller tubes called $F$. The smallest tubes $F$ have air-sacs $G$ at their ends in which gaseous exchange takes place in the body of the person. Identify $A, B, C, D, E, F$ and $G$.

Which organs are attached to the two bronchi?

In the experimental setup to show that $CO_2$ is released during respiration, name the substance taken in the small test tube kept inside the conical flask. State its function and the consequence of its use.

Why must the respiratory surface of animals always be moist?

Which process occurring in the human body does not involve energy derived directly from respiration?